1. Field
The field of the invention is endless track laying vehicles and more particularly those having two or more endless belt, sprocket driven tracks.
2. State of the Art
Vehicles adapted to utilize endless tracks of fixed width are old in the art, as are the use of sprocket wheels and wheel bogie assemblies to power, support and guide the endless tracks. However, these state of the art vehicles have not been adapted to readily utilize tracks of more than a single width, as is often desireable, especially for snow-packing uses of the vehicles. A wide track vehicle is sometimes not suitable for space limited, obstruction containing areas requiring compaction. The wide tracks often do not provide sufficiently concentrated packing force. Conversely, a vehicle limited to narrow tracks in some instances requires more passes than should be necessary to compact larger areas. Theretofore, snow-packing vehicle operators have been forced to acquire the use of both narrow tracked and wide tracked vehicles. Changing vehicles to accommodate a differing track width has heretofore required extensive and expensive alterations of the vehicle chassis to lengthen or shorten wheel bogie and sprocket wheel axles, and changing the vehicle back again has been just as costly and time consuming. On some occasions, wider or narrower tracks have been installed on existing vehicles without chassis alteration, by adapting tracks for non-symmetrical installation upon the sprockets and bogies. Such tracks do not, however, evenly pack the snow, since the force upon the snow beneath these unsymmetrically mounted tracks is not evenly distributed, the tracks tilting from the horizontal and leaving slanted impressions in the snow.